This is one of those nights when an ordinary american teaches all of us lessons about courage and the kind of resolve that can save lives. She's that school clerk who convinced a 20-year-old man who put down his gun at the elementary school in atlanta filled with so many tiny school children. Last night right here on "world news" she first told her amazing story, but now abc's steve osunsami has the 911 tapes that prove she was even more amazing than we thought. Reporter: It's a heart stopping call to police. You can hear the sound of fun fire. I'm in the front office. She just went outside and started shooting. He said to tell them to back off. He doesn't want the kids. She wants the police. So back off and, um, what else, sir? He said he don't care if he die. He don't have nothing to live for. He said he's not mentally able. Antoinette tough, the clerk the gunman confronted stayed on the phone with police after the bullets started flying. It was scary. I knew at that moment he was ready to take my life along with his and if I didn't say the right thing we all would be dead. Reporter: She followed his orders. Then she tried to get inside his head. I can help you. Do you want me to -- you want me to talk to them and try? Okay, but let me talk to them and let's see if we can work it out so you don't have to go with a wa them for a long time. Reporter: She told him her story. You going to be okay. I thought the same thing. You know, I tried to commit suicide last year after my husband left me. But look at me now. I'm still working and everything is okay. Reporter: She promised to risk her own life to help him surrender safely and that's when he got on the ground and put the guns aside. It's going to be all right. I want you to know that I love you and I'm proud of you. That's a good thing that you just given up and don't worry about it. We all go through something in life. Reporter: This is where she buzzes the police in and this is where she breaks down. I never been so scared in all my life. You did great. Oh, jesus. You did great. I god. Reporter: Today police told us the 20-year-old michael brandon hill was carrying an ak-47 that he took from a friend's home. His family say he has a history of psychiatric issues and he was off his meds. She's an every day person who did something extraordinary. It makes you recognize how school workers can set aside their issues to deal with everyone else's. By the way, antoinette told me last night that her pastor showed her how to stay calm and pray on the inside in the midst of chaos and so she did.

This transcript has been automatically generated and may not be 100% accurate.

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